Interdigitation of waveforms for dual-output electrosurgical generators

ABSTRACT

Disclosed are systems, devices, and methods for interdigitation of waveforms for dual-output electrosurgical generators. Such methods may comprise outputting DC energy from a power supply, converting DC energy from the power supply, by a plurality of amplifiers coupled to the power supply, into a plurality of RF waveforms, and controlling the plurality of RF amplifiers to interdigitate the first and second RF waveforms.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the benefit of and priority to U.S.Provisional Application Ser. No. 62/141,594, filed on Apr. 1, 2015, theentire contents of which are incorporated herein by reference.

BACKGROUND

Technical Field

The present disclosure relates to an electrosurgical system and methodfor operating an electrosurgical generator. More particularly, thepresent disclosure relates to a system, method and apparatus forinterdigitation of electrosurgical waveforms generated by radiofrequencyresonant inverters.

Background of Related Art

Electrosurgery involves application of high radio frequency electricalcurrent to a surgical site to cut, ablate, or coagulate tissue. Inmonopolar electrosurgery, a source or active electrode delivers radiofrequency alternating current from the electrosurgical generator to thetargeted tissue and a return electrode conducts the current back to thegenerator. A patient return electrode is placed remotely from the activeelectrode to conduct the current to the generator.

In bipolar electrosurgery, return and active electrodes are placed inclose proximity to each other such that an electrical circuit is formedbetween the two electrodes (e.g., in the case of an electrosurgicalforceps). In this manner, the applied electrical current is limited tothe body tissue positioned between the electrodes. Accordingly, bipolarelectrosurgery generally involves the use of instruments where it isdesired to achieve a focused delivery of electrosurgical energy betweentwo electrodes positioned on the instrument, e.g. forceps or the like.

Electrosurgical generators may have multiple outputs to power multipleelectrosurgical instruments. When multiple instruments connected to amultiple output electrosurgical generator are activated, the generatordelivers the programmed power to the parallel combination of connectedinstruments. However, prior art generators were not capable of equallydistributing power to multiple instruments. Since it was unlikely thatmultiple instruments would be activated at the exact same time and usedon the exact same impedances of tissue, it was not possible to obtainconsistent performance with multiple instruments connected to multipleoutputs of the electrosurgical generator. Thus, simultaneous activationof multiple instruments using existing generators resulted in poorperformance, and in situations where multiple surgeons were operating ona patient simultaneously the results were unpredictable. As a resultmultiple electrosurgical generators were utilized to provide acceptableperformance. Accordingly, there is a need for an electrosurgicalgenerator configured to power multiple electrosurgical instruments thatare usable simultaneously and to regulate individually the specifiedoutput power for each of the instruments coupled to the generator.

SUMMARY

The present disclosure describes interdigitating waveforms correspondingto power output generated by a dual-output electrosurgical generator.Provided in accordance with the disclosure are devices, systems, andmethods for interdigitating such waveforms.

In an aspect of the present disclosure, an electrosurgical generatorcomprises a power supply configured to output DC energy, a plurality ofRF amplifiers coupled to the power supply, each of the plurality of RFamplifiers being configured to convert DC energy from the power supplyinto an RF waveform, thereby generating a plurality of RF waveforms, anda controller coupled to the power supply and the plurality of RFamplifiers and configured to control the plurality of RF amplifiers tointerdigitate the RF waveforms generated by the plurality of RFamplifiers.

In a further aspect of the present disclosure, the electrosurgicalgenerator comprises a plurality of sensors coupled to the plurality ofRF amplifiers, each of the plurality of sensors configured to measure atleast one property of a corresponding RF waveform of the plurality of RFwaveforms supplied by a corresponding RF amplifier of the plurality ofRF amplifiers.

In yet a further aspect of the present disclosure, the controller isfurther coupled to the plurality of sensors and is further configured tocontrol the plurality of RF amplifiers based on the at least oneproperty of the corresponding RF waveform.

In another aspect of the present disclosure, the plurality of RFwaveforms are square waveforms.

In yet another aspect of the present disclosure, the controller isfurther configured to adjust the DC energy supplied by the power supplyto the plurality of RF amplifiers based on at least one property of atleast one RF waveform of the plurality of RF waveforms.

In another aspect of the present disclosure, at least one of theplurality of RF amplifiers is a non-resonant RF amplifier.

In an aspect of the present disclosure, a system for interdigitatingwaveforms for a dual-output electrosurgical generator comprises thedual-output electrosurgical generator which comprises a power supplyconfigured to output DC energy, a plurality of RF amplifiers coupled tothe power supply, each of the plurality of RF amplifiers beingconfigured to convert DC energy from the power supply into an RFwaveform, thereby generating a plurality of RF waveforms, and acontroller coupled to the power supply and the plurality of RFamplifiers and configured to control the plurality of RF amplifiers tointerdigitate the RF waveforms generated by the plurality of RFamplifiers, and at least two electrosurgical instruments operativelycoupled to the dual-output electrosurgical generator, wherein each ofthe electrosurgical instruments is coupled to one of the plurality of RFamplifiers.

In another aspect of the present disclosure, the electrosurgicalgenerator further comprises a plurality of sensors coupled to theplurality of RF amplifiers, each of the plurality of sensors configuredto measure at least one property of a corresponding RF waveform of theplurality of RF waveforms supplied by a corresponding RF amplifier ofthe plurality of RF amplifiers.

In a further aspect of the present disclosure, the controller is furthercoupled to the plurality of sensors and is further configured to controlthe plurality of RF amplifiers based on the at least one property of thecorresponding RF waveform.

In another aspect of the present disclosure, the plurality of RFwaveforms are square waveforms.

In yet another aspect of the present disclosure, the controller isfurther configured to adjust the DC energy supplied by the power supplyto the plurality of RF amplifiers based on at least one property of atleast one RF waveform of the plurality of RF waveforms.

In another aspect of the present disclosure, at least one of theplurality of RF amplifiers is a non-resonant RF amplifier.

In an aspect of the present disclosure, a method for interdigitatingwaveforms for a dual-output electrosurgical generator comprisesoutputting DC energy from a power supply, converting DC energy from thepower supply, by a plurality of amplifiers coupled to the power supply,into a plurality of RF waveforms, and controlling the plurality of RFamplifiers to interdigitate the first and second RF waveforms.

In another aspect of the present disclosure, the method furthercomprises measuring at a plurality of sensors coupled to the pluralityof RF amplifiers at least one property of a corresponding RF waveform ofthe plurality of RF waveforms supplied by a corresponding RF amplifierof the plurality of RF amplifiers.

In a further aspect of the present disclosure, the method furthercomprises controlling the at least one of the plurality of RF amplifiersbased on the at least one property of an RF waveform generated by the atleast one of the plurality of RF amplifiers.

In another aspect of the present disclosure, the plurality of RFwaveforms are square waveforms.

In yet another aspect of the present disclosure, the method furthercomprises adjusting the DC energy supplied by the power supply to theplurality of RF amplifiers based on at least one property of at leastone RF waveform of the plurality of RF waveforms.

In another aspect of the present disclosure, at least one of theplurality of RF amplifiers is a non-resonant RF amplifier.

Any of the above aspects and embodiments of the present disclosure maybe combined without departing from the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure are described herein withreference to the drawings wherein:

FIG. 1 is a perspective view of an electrosurgical system according toan embodiment of the present disclosure;

FIG. 2 is a front view of the electrosurgical generator of FIG. 1according to an embodiment of the present disclosure;

FIG. 3 is a schematic, block diagram of the electrosurgical generator ofFIG. 12 according to an embodiment of the present disclosure;

FIG. 4 is a schematic, block diagram of a DC-DC converter and a DC-ACinverter of the electrosurgical generator of FIG. 1 according to anembodiment of the present disclosure;

FIG. 5 is a graphical representation of power output levels of theelectrosurgical generator of FIG. 1 having multiple outputs according toan embodiment of the present disclosure;

FIG. 6 is another graphical representation of power output levels of theelectrosurgical generator of FIG. 1 having multiple outputs according toan embodiment of the present disclosure.

DETAILED DESCRIPTION

Particular embodiments of the present disclosure are describedhereinbelow with reference to the accompanying drawings. In thefollowing description, well-known functions or constructions are notdescribed in detail to avoid obscuring the present disclosure inunnecessary detail.

According to embodiments of the present disclosure, an electrosurgicalgenerator including at least a power supply and a plurality ofamplifiers may be configured to power multiple instrumentssimultaneously. As described in more detail below, by interdigitatingthe waveforms corresponding to the energy output by each of theplurality of amplifiers, a peak power output, and thus the load on thepower supply in, may be reduced.

A generator according to the present disclosure is configured to outputelectrosurgical energy suitable for performing monopolar and/or bipolarelectrosurgical procedures, including, but not limited to, cutting,coagulation, ablation, and vessel sealing procedures. The generator mayinclude a plurality of outputs for interfacing with variouselectrosurgical instruments (e.g., a monopolar instrument, returnelectrode, bipolar electrosurgical forceps, footswitch, etc.). Further,the generator includes electronic circuitry configured to generate radiofrequency energy specifically suited for various electrosurgical modes(e.g., cut, blend, coagulate, division with hemostasis, fulgurate,spray, etc.) and procedures (e.g., monopolar, bipolar, vessel sealing).

FIG. 1 is a schematic illustration of a bipolar and monopolarelectrosurgical system 1 according to the present disclosure. System 1may include one or more monopolar electrosurgical instruments 2 havingone or more active electrodes 3 (e.g., electrosurgical cutting probe,ablation electrode(s), etc.) for treating tissue of a patient.Electrosurgical alternating current is supplied to instrument 2 by agenerator 200 via a supply line 4 that is connected to an activeterminal 230 a, 230 b (FIG. 3) of generator 200, allowing instrument 2to cut, coagulate, ablate and/or otherwise treat tissue. The alternatingcurrent is returned to generator 200 through a return electrode 6 via areturn line 8 at a return terminal 232 a, 232 b (FIG. 3) of generator200. For monopolar operation, system 1 may include a plurality of returnelectrode pads 6 that, in use, are disposed on a patient to minimize thechances of tissue damage by maximizing the overall contact area with thepatient. In addition, generator 200 and return electrode pads 6 may beconfigured for monitoring so-called “tissue-to-patient” contact toensure that sufficient contact exists therebetween to further minimizechances of tissue damage.

System 1 may also include one or more bipolar electrosurgicalinstruments, for example, a bipolar electrosurgical forceps 10 havingone or more electrodes for treating tissue of a patient. Electrosurgicalforceps 10 includes a housing 11 and opposing jaw members 13 and 15disposed at a distal end of a shaft 12. Jaw members 13 and 15 have oneor more active electrodes 14 and a return electrode 16 disposed therein,respectively. Active electrode 14 and return electrode 16 are connectedto generator 200 through a cable 18 that includes supply and returnlines 4, 8 coupled to active and return terminals 230 a, 230 b, and 232a, 232 b, respectively (FIG. 3). Electrosurgical forceps 10 is coupledto generator 200 at a connector having connections to active and returnterminals 230 and 232 (e.g., pins) via a plug disposed at the end ofcable 18, wherein the plug includes contacts from supply and returnlines 4, 8 as described in more detail below.

With reference to FIG. 2, a front face 240 of generator 200 is shown.Generator 200 may be any suitable type (e.g., electrosurgical,microwave, etc.) and may include a plurality of connectors 250-262 toaccommodate various types of electrosurgical instruments (e.g.,electrosurgical forceps 10, etc.).

Generator 200 includes a user interface 241 having one or more displayscreens or information panels 242, 244, 246 for providing the user withvariety of output information (e.g., intensity settings, treatmentcomplete indicators, etc.). Each of screens 242, 244, 246 is associatedwith a corresponding connector 250-262. Generator 200 includes suitableinput controls (e.g., buttons, activators, switches, touch screen, etc.)for controlling generator 200. Display screens 242, 244, 246 are alsoconfigured as touch screens that display a corresponding menu for theelectrosurgical instruments (e.g., electrosurgical forceps 10, etc.).The user then adjusts inputs by simply touching corresponding menuoptions.

Screen 242 controls monopolar output and the devices connected toconnectors 250 and 252. Connector 250 is configured to couple to amonopolar electrosurgical instrument (e.g., electrosurgical instrument2) and connector 252 is configured to couple to a foot switch (notshown). The foot switch provides for additional inputs (e.g.,replicating inputs of generator 200). Screen 244 controls monopolar andbipolar output and the devices connected to connectors 256 and 258.Connector 256 is configured to couple to other monopolar instruments.Connector 258 is configured to couple to a bipolar instrument (notshown).

Screen 246 controls bipolar sealing procedures performed by forceps 10that may be plugged into connectors 260 and 262. Generator 200 outputsenergy through connectors 260 and 262 suitable for sealing tissuegrasped by forceps 10. In particular, screen 246 outputs a userinterface that allows the user to input a user-defined intensitysetting. The user-defined setting may be any setting that allows theuser to adjust one or more energy delivery parameters, such as power,current, voltage, energy, etc. or sealing parameters, such as energyrate limiters, sealing duration, etc. The user-defined setting istransmitted to controller 224 where the setting may be saved in memory226. In embodiments, the intensity setting may be a number scale, forexample, from one to ten or one to five. In embodiments, the intensitysetting may be associated with an output curve of generator 200. Theintensity settings may be specific for each forceps 10 being utilized,such that various instruments provide the user with a specific intensityscale corresponding to forceps 10.

Generator 200 according to the present disclosure is a non-resonantgenerator and may include dual or multiple outputs to simultaneouslypower multiple instruments.

The generator 200 may be configured to operate in any of a constantvoltage limit mode, a constant current limit mode, a constant powermode, and combinations thereof. The mode selection is generally based onthe impedance associated with the tissue being cut. Different types oftissue, such as muscle and fat, have different impedances. In terms ofelectrosurgical operations, constant power output tends to uniformlyvaporize tissue, resulting in clean dissection. Whereas constant voltageoutput tends to explosively vaporize or carbonize tissue (“blackcoagulation”), and constant current output tends to thermally coagulatetissue without vaporization (“white coagulation”). Carbonization issurgically useful if the surgeon wishes to rapidly destroy surfacetissue, and thermal coagulation is regularly coupled with mechanicalpressure to seal hepatic or lymphatic vessels shut. However, the surgeongenerally desires to operate using constant power output andimportantly, return to using constant power output as quickly aspossible if there is deviation.

With respect to the AC output of the generator 200 and in exemplaryembodiments, “constant power” is defined to mean the average powerdelivered in each switching cycle is substantially constant. Likewise,“constant voltage” and “constant current” are defined as modes where theroot mean square (RMS) value of the AC voltage or current, respectively,is regulated to a substantially fixed value. An exemplary graphicalrepresentation of the desired output characteristics is illustrated inFIG. 5. In an exemplary embodiment, as the load impedance increases andvoltage increases, the corresponding increasing output voltage triggersa transition from a constant current mode shown as region A to aconstant power mode shown as region B and to a constant voltage modeshown as region C. Similarly, in an exemplary embodiment, as the loadimpedance decreases and current increases, the corresponding decreasingoutput voltage triggers the opposite transition from the constantvoltage region C to the constant power region B and to the constantcurrent region A.

FIG. 3 shows a schematic block diagram of generator 200 configured tooutput electrosurgical energy. Generator 200 includes a controller 224,a power supply 227, radiofrequency (RF) amplifiers 228 a, 228 b, andsensors 280 a, 280 b. Power supply 227 may be a high voltage, DC powersupply connected to an AC source (e.g., line voltage) and provides highvoltage, DC power to RF amplifiers 228 a, 228 b, which then convertshigh voltage, DC power into treatment energy (e.g., electrosurgical ormicrowave) and delivers the energy to active terminals 230 a, 230 b,respectively. The energy is returned thereto via return terminals 232 a,232 b. RF amplifiers 228 a, 228 b are configured to operate in aplurality of modes, during which generator 200 outputs correspondingwaveforms having specific duty cycles, peak voltages, crest factors,etc. It is envisioned that in other embodiments, generator 200 may bebased on other types of suitable power supply topologies. RF amplifiers228 a, 228 b may be non-resonant RF amplifiers. A non-resonant RFamplifier, as used herein, denotes an amplifier lacking any tuningcomponents, i.e., conductors, capacitors, etc., disposed between the RFinverter and the load.

Controller 224 includes a processor 225 operably connected to a memory226, which may include transitory type memory (e.g., RAM) and/ornon-transitory type memory (e.g., flash media, disk media, etc.).Processor 225 includes an output port that is operably connected topower supply 227 and/or RF amplifiers 228 a, 228 b allowing processor225 to control the output of generator 200 according to either openand/or closed control loop schemes. A closed loop control scheme is afeedback control loop, in which a plurality of sensors 280 a, 280 bmeasure a variety of tissue and energy properties (e.g., tissueimpedance, tissue temperature, output power, current and/or voltage,etc.), and provide feedback to controller 224. Controller 224 thensignals power supply 227 and/or RF amplifiers 228 a, 228 b, whichadjusts the DC and/or power supply, respectively. Those skilled in theart will appreciate that processor 225 may be substituted for by usingany logic processor (e.g., control circuit) adapted to perform thecalculations and/or set of instructions described herein including, butnot limited to, field programmable gate array, digital signal processor,and combinations thereof.

Generator 200 according to the present disclosure includes a pluralityof sensors 280 a, 280 b, i.e., RF current sensors and RF voltagesensors. Various components of generator 200, namely, RF amplifiers 228a, 228 b, and sensors 280 a, 280 b, may be disposed on a printed circuitboard (PCB). An RF current sensor may be coupled to active terminals 230a, 230 b and provide measurements of the RF current supplied by RFamplifiers 228 a, 228 b. An RF voltage sensor may be coupled to activeterminals 230 a, 230 b and return terminals 232 a, 232 b providesmeasurements of the RF voltage supplied by RF amplifiers 228 a, 228 b.

Sensors 280 a, 280 b provide the sensed RF voltage and current signals,respectively, to controller 224, which then may adjust output of powersupply 227 and/or RF amplifiers 228 a, 228 b in response to the sensedRF voltage and current signals. Controller 224 also receives inputsignals from the input controls of generator 200, instrument 2 and/orforceps 10. Controller 224 utilizes the input signals to adjust poweroutputted by generator 200 and/or performs other control functionsthereon.

With reference to the schematic shown in FIG. 4, the generator 200includes a DC-DC buck converter 101, a DC-AC boost converter 102, aninductor 103, a transformer 104, and controller 224. In embodiments, theDC-AC boost converter 102 is part of each of the RF amplifiers 228 a,228 b. Accordingly, for simplicity only one of the RF amplifiers 228 a,228 b is discussed herein below. In the exemplary embodiment, a DCvoltage source Vg, such as power supply 227, is connected to DC-DC buckconverter 101. Furthermore, inductor 103 is electrically coupled betweenDC-DC buck converter 101 and DC-AC boost converter 102. The output ofDC-AC boost converter 102 transmits power to the primary winding oftransformer 104, which passes through the secondary winding oftransformer 104 to the load Z (e.g., tissue being treated).

DC-DC buck converter 101 includes a switching element 101 a and DC-ACboost converter 102 includes a plurality of switching elements 102 a-102d arranged in an H-bridge topology. In embodiments, DC-AC boostconverter 102 may be configured according to any suitable topologyincluding, but not limited to, half-bridge, full-bridge, push-pull, andthe like. Suitable switching elements include voltage-controlled devicessuch as transistors, field-effect transistors (FETs), combinationsthereof, and the like. In an exemplary embodiment, controller 224 is incommunication with both DC-DC buck converter 101 and DC-AC boostconverter 102, in particular, the switching elements 101 a and 102 a-102d, respectively. Controller 224 is configured to output control signals,which may be a pulse-width modulated signal, to switching elements 101 aand 102 a-102 d as described in further detail in co-pending applicationpublished as US 2014/0254221, entitled CONSTANT POWER INVERTER WITHCREST FACTOR CONTROL, filed on Dec. 4, 2013 by Johnson et al., theentire contents of which is incorporated by reference herein. Inparticular, controller 224 is configured to control the duty cycle d1 ofthe control signal supplied to switching element 101 a of DC-DC buckconverter 101 and duty cycle d2 of the control signals supplied toswitching elements 102 a-102 d of DC-AC boost converter 102.Additionally, controller 224 is configured to measure powercharacteristics of generator 200, and control generator 200 based atleast in part on the measured power characteristics. Examples of themeasured power characteristics include the current through inductor 103and the voltage at the output of DC-AC boost converter 102. In anexemplary embodiment, controller 224 controls buck converter 101 bygenerating the duty cycle d1 based on a comparison of the inductorcurrent and a nonlinear carrier control current for every cycle.

FIG. 5 is a plot showing the power output levels of the generator 200.In response to one of the instruments 310 a or 310 b being activated, acorresponding RF amplifier 228 a or 228 b generates the programmedtreatment energy for the instrument. To generate treatment energy, RFamplifiers 228 a, 228 b draw DC power from shared power supply 227.

In response to both instruments 310 a and 310 b being activatedsimultaneously, each of the RF amplifiers 228 a and 228 b generatesenergy for each of the instruments 310 a and 310 b. The non-resonant RFamplifiers 228 a and 228 b according to the present disclosure areconfigured to generate square waveforms as shown in FIG. 5, rather thansine waveforms, which are generated by resonant networks that are absentfrom the RF amplifiers 228 a and 228 b. With continued reference to FIG.5, output generated by RF amplifier 228 a is represented by a firstwaveform 502 having peaks 510 and 512, and output generated by RFamplifier 228 b is represented by a second waveform 504 having peaks 514and 516. The combined output of RF amplifiers 228 a, 228 b isrepresented by peaks 518, each of which is a combination of peaks 510and 514 and peaks 512 and 516.

Thus, when instruments 310 a, 310 b are activated simultaneously, withtreatment energy being delivered in-phase, the total peak power sourcedby shared power supply 227 is the sum of individual outputs, requiringshared power supply 227 to be rated for this higher peak power. To avoidthis, the power levels drawn from shared power supply 227 may beinterspersed such that peak power levels are not drawn by multiple RFamplifiers 228 a and 228 b simultaneously. One method of interspersingpower drawing levels is by interdigitating the waveforms.Interdigitation, as used herein, denotes outputting two or morewaveforms at a specific phase relationship in which the power draw fromthe power supply 227 is substantially uniform. In one embodiment,waveforms may be interdigitated such that their respective peaks areevenly spaced and occur out of phase. The peaks of one waveform may bealigned with the valleys of the other waveform. By doing so, the powerlevels drawn balance out, and results in a constant level of power drawninstead of peaks and valleys.

FIG. 6 is a plot showing the power output levels of generator 200 whenthe waveforms generated by RF amplifiers 228 a, 228 b areinterdigitated. Output of the RF amplifier 228 a is represented by afirst waveform 602 having peaks 610, 612 and output of the RF amplifier228 b is represented by a second waveform 604 having peaks 614 and 616.The combined output of RF amplifiers 228 a, 228 b when the respectiveoutput waveforms 602 and 604 are interdigitated may be represented by asingle, continuous waveform 618, without any peaks, because the poweroutput level remains constant. Thus, when dual output waveforms areinterdigitated, as shown in FIG. 6, the peak power delivered by sharedpower supply 227 may be reduced as compared to the output illustrated inFIG. 5.

While several embodiments of the disclosure have been shown in thedrawings and/or described herein, it is not intended that the disclosurebe limited thereto, as it is intended that the disclosure be as broad inscope as the art will allow and that the specification be read likewise.Therefore, the above description should not be construed as limiting,but merely as exemplifications of particular embodiments. Those skilledin the art will envision other modifications within the scope and spiritof the claims appended hereto.

What is claimed is:
 1. An electrosurgical generator, comprising: a powersupply configured to output DC energy; a plurality of RF amplifierscoupled to the power supply, each of the plurality of RF amplifiersbeing configured to convert DC energy from the power supply into an RFwaveform, thereby generating a plurality of RF waveforms; a plurality ofpairs of output terminals, each pair including an active terminal and areturn terminal, each of the pairs of output terminals is independentlyconnected to one of the plurality of RF amplifiers and is configured toindependently connect to an electrosurgical instrument of a plurality ofelectrosurgical instruments; and a controller coupled to the powersupply and the plurality of RF amplifiers and configured to control theplurality of RF amplifiers to interdigitate the RF waveforms generatedby the plurality of RF amplifiers.
 2. The electrosurgical generatoraccording to claim 1, further comprising a plurality of sensors coupledto the plurality of RF amplifiers, each of the plurality of sensorsconfigured to measure at least one property of a corresponding RFwaveform of the plurality of RF waveforms supplied by a corresponding RFamplifier of the plurality of RF amplifiers.
 3. The electrosurgicalgenerator according to claim 2, wherein the controller is furthercoupled to the plurality of sensors and is further configured to controlthe plurality of RF amplifiers based on the at least one property of thecorresponding RF waveform.
 4. The electrosurgical generator according toclaim 1, wherein the controller is further configured to adjust the DCenergy supplied by the power supply to the plurality of RF amplifiersbased on at least one property of at least one RF waveform of theplurality of RF waveforms.
 5. The electrosurgical generator according toclaim 1, wherein at least one of the plurality of RF amplifiers is anon-resonant RF amplifier.
 6. A system for interdigitating waveforms fora dual-output electrosurgical generator, the system comprising: adual-output electrosurgical generator, comprising: a power supplyconfigured to output DC energy; a plurality of RF amplifiers coupled tothe power supply, each of the plurality of RF amplifiers beingconfigured to convert DC energy from the power supply into an RFwaveform, thereby generating a plurality of RF waveforms; a plurality ofpairs of output terminals, each pair including an active terminal and areturn terminal, each of the pairs of output terminals is independentlyconnected to one of the plurality of RF amplifiers; and a controllercoupled to the power supply and the plurality of RF amplifiers andconfigured to control the plurality of RF amplifiers to interdigitatethe RF waveforms generated by the plurality of RF amplifiers; and atleast two electrosurgical instruments, each of which is operativelycoupled to one of the plurality of pairs of output terminals of thedual-output electrosurgical generator, wherein each of theelectrosurgical instruments is coupled to one of the plurality of RFamplifiers.
 7. The system according to claim 6, wherein theelectrosurgical generator further comprises a plurality of sensorscoupled to the plurality of RF amplifiers, each of the plurality ofsensors configured to measure at least one property of a correspondingRF waveform of the plurality of RF waveforms supplied by a correspondingRF amplifier of the plurality of RF amplifiers.
 8. The system accordingto claim 7, wherein the controller is further coupled to the pluralityof sensors and is further configured to control the plurality of RFamplifiers based on the at least one property of the corresponding RFwaveform.
 9. The system according to claim 6, wherein the controller isfurther configured to adjust the DC energy supplied by the power supplyto the plurality of RF amplifiers based on at least one property of atleast one RF waveform of the plurality of RF waveforms.
 10. The systemaccording to claim 6, wherein at least one of the plurality of RFamplifiers is a non-resonant RF amplifier.
 11. A method forinterdigitating waveforms for a dual-output electrosurgical generator,the method comprising: outputting DC energy from a power supply;converting DC energy from the power supply, by a plurality of RFamplifiers coupled to the power supply, into a plurality of RFwaveforms; transmitting each of the plurality of RF waveforms to one ofa plurality of pairs of output terminals, each pair including an activeterminal and a return terminal, each of the pairs of output terminals isindependently connected to one of the plurality of RF amplifiers and toan electrosurgical instrument of a plurality of electrosurgicalinstruments; and controlling the plurality of RF amplifiers tointerdigitate the plurality of RF waveforms through the plurality ofelectrosurgical instruments.
 12. The method according to claim 11,further comprising measuring at a plurality of sensors coupled to theplurality of RF amplifiers at least one property of a corresponding RFwaveform of the plurality of RF waveforms supplied by a corresponding RFamplifier of the plurality of RF amplifiers.
 13. The method according toclaim 12, further comprising controlling the at least one of theplurality of RF amplifiers based on the at least one property of an RFwaveform generated by the at least one of the plurality of RFamplifiers.
 14. The method according to claim 11, further comprisingadjusting the DC energy supplied by the power supply to the plurality ofRF amplifiers based on at least one property of at least one RF waveformof the plurality of RF waveforms.
 15. The method according to claim 11,wherein at least one of the plurality of RF amplifiers is a non-resonantRF amplifier.